tests workflow (nschloe/pytest-codeblocks)

The tests workflow from nschloe/pytest-codeblocks, explained and optimized by Latchkey.

What it does

This is the tests workflow from the nschloe/pytest-codeblocks repository, a real project running GitHub Actions. It is shown here with attribution under its MIT license.

Below, Latchkey shows a faster, safer version produced by its optimization engine.

The workflow

name: tests

on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - uses: j178/prek-action@v2

  build:
    needs: [lint]

    strategy:
      matrix:
        platform: [ubuntu-latest, macos-latest, windows-latest]
        python-version: ["3.10", "3.15"]

    runs-on: ${{ matrix.platform }}

    steps:
      - uses: actions/checkout@v6

      - uses: astral-sh/setup-uv@v7
        with:
          python-version: ${{ matrix.python-version }}

      - name: Test
        run: |
          uv run pytest

The same workflow, on Latchkey

Removes redundant runs and caps runaway jobs. Added and changed lines are highlighted.

name: tests
 
on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  lint:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
      - uses: actions/checkout@v6
      - uses: j178/prek-action@v2
 
  build:
    timeout-minutes: 30
    needs: [lint]
 
    strategy:
      matrix:
        platform: [ubuntu-latest, macos-latest, windows-latest]
        python-version: ["3.10", "3.15"]
 
    runs-on: ${{ matrix.platform }}
 
    steps:
      - uses: actions/checkout@v6
 
      - uses: astral-sh/setup-uv@v7
        with:
          python-version: ${{ matrix.python-version }}
 
      - name: Test
        run: |
          uv run pytest
 

What changed

• Run on Latchkey managed runners with one line (runs-on), which apply the fixes below automatically and self-heal transient failures. This example uses latchkey-small; pick the runner size that fits the job.
• Cancel superseded runs when a branch or PR gets a newer push.
• Add a job timeout so a hung step cannot burn hours of runner time.

2 third-party actions are referenced by a movable tag. Pin them to the commit SHA (Latchkey resolves and applies this automatically) so a repointed tag cannot change what runs.

This workflow runs 2 jobs (7 with the matrix expanded) per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow